Enoplometopus holthuisi Gordon, 1968

Poupin, Joseph, 2003, Reef lobsters Enoplometopus A. Milne Edwards, 1862 from French Polynesia, with a brief revision of the genus (Crustacea, Decapoda, Enoplometopidae), Zoosystema 25 (4), pp. 643-664 : 652-655

Enoplometopus holthuisi Gordon, 1968

( Figs 6 ; 7 )

Enoplometopus holthuisi Gordon, 1968: 90 (type locality: Banda Islands, Moluccas, Indonesia).

Enoplometopus holthuisi – Intès & Le Loeuff 1970: 1442 (text). — Burukovsky 1983: 153 (key). — Daum 1982: 265 ( Philippines; pro parte, only illustration p. 265). — Türkay 1989: 228 (Hawaii). — Bonvallot et al. 1994: 144 (Tuamotu). — Poupin 1996b: 8 (checklist). — Chan 1998: 998, 1000 (western Pacific). — Chan & Yu 1998: 189 (key). — Debelius 1999: 204 (Hawaii).

Enoplometopus (Hoplometopus) holthuisi – Holthuis 1983: 297 ( Marshall Islands; Hawaii).

Hoplometopus holthuisi – de Saint Laurent 1988: 61 (list). — Gosliner et al. 1996: 220 (Hawaii). — Hoover 1998: 241 (Hawaii).

Enoplometopus antillensis – Holthuis 1946: 79 ( Moluccas) (non Enoplometopus antillensis Lütken, 1865 , except for pl. V, fig. h and pl. VII, fig. b, drawn from type specimen of E. antillensis ).

Enoplometopus occidentalis – George & George 1979: 78 (photograph) (non Enoplometopus occidentalis ( Randall, 1840)) .

Hoplometopus sp. nov. – Poupin 1996a: 14 ( French Polynesia) (non sp. nov. = E. holthuisi , see Remarks).

Non Enoplometopus holthuisi – Daum 1982: 266 (illustrated specimen belongs to E. voigtmanni ). — Allen & Steene 1994: 145 (photograph = E. voigtmanni ).

MATERIAL EXAMINED. — French Polynesia. Austral Islands, Rurutu, Frv Marara , stn 423, 22°29.3’S, 151°21.6’W, trap 80 m, 10.VIII.1991, 1 ♂ cl 28 mm, bl 96 mm ( MNHN As 624). — Society Islands, Tahiti, dry remains of chelae only with this label “ Hoplometopus gordonae sp. nov. ” ( MNHN As 625).

Indonesia. Banda Islands, V.1921, leg. E. Van der Velde, 1 ♀ holotype cl 33 mm, bl 105 mm, 1 ♂ paratype cl 30 mm, bl 93 mm ( ZMA De 101.265).

La Réunion. 1973, coll. Y. Plessis, 1 ♂ cl 22.5 mm, bl 74.5 mm ( MNHN As 271).

DISTRIBUTION. — West Indian Ocean to central Pacific : La Réunion, Indonesia ( Banda Islands , Moluccas), Philippines, Marshall Islands ( Enawetak atoll), Hawaii , French Polynesia ( Austral Islands : Rurutu ; Society Islands : Tahiti ; Tuamotu Islands). Depths: 20-80 m. On hard bottoms.

SHORT DESCRIPTION

(SPECIMEN FROM FRENCH POLYNESIA)

Rostrum with three spines on lateral margin. Carapace with five median, two postcervical, one intermediate, one supraocular, and three lateral spines ( Fig. 7A ). Chela 4.6 times as long as wide, palm ovate in cross section ( Fig. 7C ). Upper and lower faces of palm smooth; outer margin with eight spines; inner margin with two rows of five spines, converging distally. Fingers 0.4 times as long as chela, with sharp inward curved crossing tips; cutting edges denticulated with five or six larger teeth; outer edges smooth, furnished with very long setae extending well beyond tip of fingers (see Remarks).

Second pereopod circular in cross section, reaching to proximal third of chela. Merus and carpus with distoventral spine. Propodus subequal to merus, furnished with few long setae; distoventral angle with process armed with five to eight tiny spines on upper margin, and two mobile spines, distally ( Fig. 7D ). Dactyl short, 0.2 times as long as propodus. Pereopod 3 and 4 shorter than P2, with terminal pincers reduced. Pereopod 5 is the shortest and has no terminal pincer.

Pleura of abdominal somites II-V, each with sharp, posteriorly curved tooth; pleuron of somite VI with blunt tooth ( Fig. 7B ). Posterior margin of tergite VI with three median tubercles flanked by two short spines ( Fig. 7E ). Male first pleopod subrectangular with deep incision on distal margin ( Fig. 7F ). Telson with two lateral spines of similar size and two distolateral spines, inner one longer ( Fig. 7E ).

Coloration ( Fig. 6 )

Ground color of body orange with white at tip of spines. Lateral face of carapace with large white circle, on distal half, and wavy white lines on proximal half. Abdominal somites with white spots bordered by dark orange rings, as illustrated on Figure 6 . Chela orange with faint reticulated lines on palm, and alternated dark and light orange bands on fingers. Ambulatory legs banded in white and orange on whole length.

REMARKS

Because of the particular shape of its chela that is distinct from typical E. holthuisi , the specimen trapped around the French Polynesian islands had been previously attributed to a new species ( Poupin 1996a). In this work it has been compared carefully with the holotype of E. holthuisi , which confirms the distinctive shape of its chela (cf. Fig. 7C with Fig. 7G ). It is less elongated, being 4.6 times as long as wide, vs 6.4 in holotype, and has shorter fingers, 0.4 times as long as chela, instead of 0.5 in holotype. Outer edges of the fingers are also furnished with very long setae ( Fig. 6B ), absent on the holotype and never observed on photographs of E. holthuisi consulted during this study. Despite these obvious differences, all other characters of the Polynesian specimen are those of E. holthuisi , particularly the shape of male first pleopod, a very distinctive character in this species. It thus seems that the peculiar shape of its chela must be attributed to its small size.

Enoplometopus holthuisi is related to E. voigtmanni . As denoted in the Remarks of E. gracilipes , the two species are easily separated by their coloration, in particular the lateral face of the carapace which has a large white circle, in E. holthuisi , and a network of streaks, in E. voigtmanni . They also differ by the shape of the spines on the abdominal pleura II-V, as illustrated in Türkay (1989: figs 1, 2b). When male first pleopod is known in E. voigtmanni it will be interesting to check if the two species can also be separated by the shape of this appendage. Enoplometopus holthuisi is also related to E. gracilipes , and the differences between the two species have been listed under E. gracilipes . It is interesting to point out that the single specimen of E. holthuisi caught during the fishing operations of the Frv Marara (stn 423, 80 m) was associated in the trap with E. gracilipes . Enoplometopus holthuisi is usually reported in shallow waters, between 20-50 m, while E. gracilipes is mostly caught at depths greater than 100 m. Therefore, it appears that these two species can co-occur at intermediate depths, between 50- 100 m.

Figures

FIG. 6. — Enoplometopus holthuisi Gordon, 1968, ♂ cl 28 mm, Austral Islands (MNHN As 624); A, lateral view; B, dorsal view.

FIG. 7. — Enoplometopus holthuisi Gordon, 1968, ♂ cl 28 mm, Austral Islands (MNHN As 624); A, carapace, dorsal view; B, abdomen, lateral view; C, left chela, dorsal view; D, dactyl and distal part of propodus of left second pereopod, outer view; E, posterior margin of tergite 6 and telson, dorsal view; F, right first pleopod, outer view, ♀ holotype cl 33 mm, Banda Islands (ZMA De 101.265); G, left chela dorsal view (setae omitted). Scale bars: 5 mm.